TIANJIN, China (Reuters) - China’s Premier Li Keqiang said on Wednesday that multi-lateralism should be upheld, and that unilateral trade actions will not solve any problems.

The trend of globalisation is unstoppable, even though there are flaws in the process, and the basic principle of free trade should be maintained, Li said in a speech at the World Economic Forum in Tianjin.

China’s process of opening up will only quicken, Li said.

China and the United States plunged deeper into a trade war on Tuesday after Beijing added $60 billion of U.S. products to its import tariff list in retaliation for President Donald Trump’s planned levies on $200 billion worth of Chinese goods.